The functions of the Statistical Office of the Southwest Oncology Group are: (1) to provide analyses of on-going clinical studies in cooperation with the chairman of each study; (2) to achieve the objective in (1), provides for the central registration of all patients and studies, and provides for the surveillance, monitoring, storage, and processing of data collected during Group studies; (3) to provide for the review of all proposed protocols and to suggest an experimental design for each study; (4) to work in close cooperation with the Chairman of the Southwest Oncology Group in the administration of Group studies; (5) to perform research on the statistical aspects of Group studies to improve the efficiency of on-going and future clinical trials; (6) to carry out long-term analyses of Group studies to determine, for example, whether survival has been improving with time, and which clinical and laboratory variables seem important in relation to the response and survival of a cancer patient. The Statistical Office of the SWOG also provides statistical services to the Pediatric Intergroup Rhabdomyosarcoma Study and the Pediatric Intergroup Ewing's Sarcoma Study. Both studies involve patients from Acute Leukemia Group B, Children's Cancer Study Group A, and the Southwest Oncology Group.